Today, on MLKjr day, I'd like to point out that the tendency for a state's politics to be dominated by a single party has made life difficult for oppressed minority groups, especially in the South. Politicians who always need to get a plurality of the votes will push the issues that please most (white) voters. And this has led to support for racial discrimination as part of "state's rights". This is part of institutional racism, something that we still must struggle with in the USA to do the right thing.
But what if it were impossible for either of the two major parties to dominate a state's politics? And what if third party state assembly-persons could get elected with as little as 10% of the vote in their district? Wouldn't that be a hurdle low enough for a minority group to elect one of their own members? Then, what if the third party assembly-person then got to help determine which of the two major parties is in power in the state assembly? The incentives for the major parties would be different. The return to pandering to the majority of voters on the wrong issues would be lower and there would be a higher incentive to protect the rights of minority groups.